Browsing by Author "Manageiro, Vera"
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- GES-5 among the b-lactamases detected in ubiquitous bacteria isolated from aquatic environment samplesPublication . Manageiro, Vera; Ferreira, Eugénia; Canica, Manuela; Manaia, Celia M.In this study, we investigated the b-lactamase-encoding genes responsible for b-lactam resistance phenotypes detected among 56 Gram-negative isolates (Gamma- and Alpha-proteobacteria) recovered from wastewater, urban streams, and drinking water. The b-lactam resistance mechanisms detected in 36 isolates comprised the presence of class A (blaTEM-1, blaSHV-1, blaSHV-11, blaGES-5), class B (ImiS, L1), class C (blaCMY-2, blaCMY-34, blaCMY-65, blaCMY-89, blaCMY-90, blaACC-5, blaACT-13), and class D (blaOXA-309)b-lactamase-encoding genes, some variants described for the first time here. Notably, the results showed antimicrobial resistance genes related not only to commonly used antibiotics, but also to carbapenems, providing the first description of a GES-5-producing Enterobacteriaceae. The importance of ubiquitous bacteria thriving in aquatic environments as reservoirs or carriers of clinically relevant resistance determinants was confirmed, and the need to monitor water habitats as potential sources for the emergence and/or spread of antibiotic resistance in the environment was highlighted.
- Molecular evidence of the close relatedness of clinical, gull and wastewater isolates of quinolone-resistant Escherichia coliPublication . Varela, Ana Rita; Manageiro, Vera; Ferreira, Eugénia; Augusta Guimarães, M.; Costa, Paulo Martins da; Caniça, Manuela; Manaia, Célia M.Escherichia coli with reduced susceptibility to quinolones isolated from different environmental sources (urban wastewater treatment plants, n = 61; hospital effluent, n = 10; urban streams, n = 9; gulls, n = 18; birds of prey, n = 17) and from hospitalised patients (n = 28) were compared based on multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). The habitats with the most diversified genotypes of quinolone-resistant E. coli, corresponding to the highest genetic diversity (H'), were wastewater and gulls. In addition, genetically distinct populations were observed in clinical samples and birds of prey, suggesting the influence of the habitat or selective pressures on quinolone-resistant E. coli. The close genetic relatedness between isolates of clinical origin and from gulls and wastewater suggests the existence of potential routes of propagation between these sources. The most common sequence types were ST131 and ST10, with ST131 being highly specific to patients, although distributed in all of the other habitats except birds of prey. The prevalence of antimicrobial resistance was significantly higher in isolates from patients and gulls than from other sources (P < 0.01), suggesting that the effect of selective pressures met by isolates subjected to strong human impacts. The evidence presented suggests the potential circulation of bacteria between the environmental and clinical compartments, with gulls being a relevant vector of bacteria and resistance genes.